Catheter introducers are a well-known form of catheter, used to assist in the introduction of other catheters and guidewires to the arteriovenous system of a patient. Such catheter introducers comprise a tubular sheath or cannula having a housing carried on one end thereof, with the housing enclosing a hemostasis valve. Examples of such catheter introducers are numerous, with some being disclosed in Stevens U.S. Pat. Nos. 4,000,739 and 4,421,296. Other examples of catheter introducers are disclosed in Kranys U.S. Pat. No. 5,207,656; Weinstein U.S. Pat. No. 4,626,245; and Hillstead U.S. Pat. No. 4,895,565.
In the devices of the above described patents, the hemostasis valve comprises a flat, elastic partition seal with a center cut, either an aperture or a slit, through which a catheter (or guidewire) passes as it extends through the catheter introducer. These flat seals must be capable of allowing passage of catheters while maintaining sufficient elasticity to snap closed after removal thereof.
By this invention a valve is provided for a catheter introducer in which different valving principles are used to provide reliable hemostasis, so that blood at arterial pressure cannot flow out of the proximal end of the catheter introducer. Also, catheters passing through the valve of this invention are provided with lubrication for improved reduction in friction as the catheter is advanced through the entire catheter introducer and into the arteriovenous system of a patient.